Which two statements describe nonstop routing? (Choose two.)
A.
RPD is running on the backup RE
B.
Graceful restart is required for nonstop routing to function.
C.
Peer nodes are not alerted of RE mastership changes.
D.
COSD is running on the backup RE
Explanation:
Enabling Nonstop RoutingNonstop routing (NSR) allows a routing platform with redundant Routing Engines to switch over from a primary Routing Engine to a backup Routing Engine without alerting peer nodes that a change has occurred. Nonstop routing uses the same infrastructure as graceful Routing Engine switchover (GRES) to preserve interface and kernel information. However, nonstop routing also saves routing protocol information by running the routing protocol process (rpd) on the backup Routing Engine. By saving this additional information, nonstop routing is self-contained and does not rely on helper routers to assist the routing platform in restoring routing protocol information. As a result of this enhanced functionality, nonstop routing is a natural replacement for graceful restart protocol extensions.
If the kernel on the master Routing Engine stops operating, the master Routing Engine experiences a hardware failure, or the administrator initiates a manual switchover, mastership switches to the backup Routing Engine. To use nonstop routing, you must first enable GRES on your routing platform. For more information about how to configure GRES, see the JUNOS High Availability Configuration Guide.
To enable nonstop routing, include the nonstop-routing statement at the [edit routing-options] hierarchy level.
[edit routing-options]nonstop-routing;
Note: You cannot configure nonstop routing and graceful restart protocol extensions simultaneously. To ensure proper operation, include either the nonstop-routing statement or the graceful-restart statement at the hierarchy level, but not both statements at the same time.
For more detailed information about nonstop routing, see the JUNOS High Availability Configuration Guide.